| Fairness is one of the principles for maintaining social stability.A large number of studies have found that people generally have a tendency to dislike unfairness and are willing to sacrifice their own interests to pursue fairness,and this tendency to sacrifice their own interests to pursue fairness is influenced by multiple factors.The ultimatum game paradigm is a classic paradigm for studying fairness.In this paradigm,there are two roles,the proposer and the responder.They need to divide a resource(usually money).The proposer has the right to decide how to allocate it.The responder can only accept or reject the proposal given by the proposer.If the responder accepts,the profits of both parties will be distributed according to the proposal.If they refuse,the profits of both parties will be zero.Existing research using this paradigm has explored the factors that affect perceived fairness and found that relative wealth and social distance are two important influencing factors.Relative wealth is one of the important factors that affect an individual’s perception of fairness,mainly referring to a subjective perception of their relative wealth formed by comparing their own wealth status with the wealth status of others or groups.The aristocratic responsibility and obligation hypothesis suggests that individuals have higher expectations of responsibility towards high-wealth groups,so when the high-wealth group is the proposer,they are less willing to accept unfair proposals from that group.The theory of social entity fairness believes that an individual’s perception of fairness is not only influenced by current situational factors,but also by a broader social background,such as greater sympathy for vulnerable groups.Therefore,when the low wealth group is the proposer,the acceptance rate of unfair proposals to that group is higher than that of the high wealth group.In addition,social distance is also an important factor affecting the perception of fairness.Social distance refers to an individual’s subjective perception or experience of distance from others,and is also used to measure the degree of intimacy between individuals and others.In the past,there were two phenomena about the impact of social distance on the perception of fairness: the theory of kinship selection believed that in order to better reproduce one’s own genes,it is a kind of reciprocity altruism to help others or friends who are related to one’s own blood.This phenomenon also exists in the ultimatum game.The acceptance rate of unfair proposals from friends is significantly higher than that of strangers.However,it is not that the closer social distance,the more tolerance towards unfairness.Some studies on the impact of social distance on perceived fairness have found another phenomenon,where individuals find it more difficult to accept unfair proposals from friends than from strangers.There are parts of previous research that have not been explored yet.Firstly,with a clear understanding of the relative wealth differences between the two parties,when facing objects with different social distances,do individuals defend the principle of fairness in fair decision-making or are they more altruistic towards friends due to the influence of social distance? Does the impact of relative wealth on the perception of fairness support the aristocratic responsibility hypothesis? Secondly,do the differences in relative wealth acquisition methods and social distance between the two parties also affect individuals’ choices in fair decision-making? This study adopts two experiments,using event related potential technology and combining behavioral and EEG indicators to further reveal the individual’s processing process of fair decisionmaking under the influence of relative wealth and social distance.Experiment 1 adapted the ultimatum game task paradigm,and the experiment design was 2(relative wealth: high,low)× 2(Social distance:friends,strangers)× 2(Proposal Type: Fair,Unfair),exploring the behavioral responses and brain motor mechanisms of individuals as responders to unfair proposals under relative wealth and social distance based on luck.The results show that:(1)In terms of behavioral outcomes,the acceptance rate of unfair proposals from friends is higher.The acceptance rate of unfair proposals for individuals with low relative wealth is higher.(2)In terms of EEG results,proponents with low relative wealth elicited larger P200 amplitudes than proponents with high relative wealth;The proposal from high relative wealth proposers induced a more negative FRN;The fair proposal of high relative wealth strangers induces a more negative FRN than the fair proposal of low relative wealth strangers;The fair proposal of low relative wealth strangers induces a greater P300 than the fair proposal of high relative wealth strangers.Experiment 2 further explores the behavioral responses and brain motor mechanisms of individuals as responders to unfair proposals under the conditions of relative wealth and social distance based on ability acquisition.Adopting 2(relative wealth: high,low)× 2(Social distance: friends,strangers)× 2(proposal type: fair,unfair).The results show that:(1)in terms of behavioral outcomes,the acceptance rate of proposals from friends is significantly higher than that of proposals from strangers;The acceptance of fair proposals is significantly higher than that of unfair proposals.(2)In terms of EEG results,suggestions from friends elicited larger P200 amplitudes than those from strangers;Unfair proposals from friends with high relative wealth induced greater P200 than those from strangers with high relative wealth;Unfair proposals from high relative wealth strangers induce a more negative FRN than those from low relative wealth strangers;Fair proposals from high relative wealth proponents induce larger P300 amplitudes than fair proposals from low relative wealth proponents.In summary,it was found that different ways of obtaining relative wealth and social distance have different impacts on individuals’ perception of fairness.The results of Experiment 1 and Experiment 2 jointly support the theory of kinship selection,while the results of Experiment 2 support the hypothesis of aristocratic responsibility and obligation. |
